Correct my SAT practice essay?

You are trying to write in the highest level you can which is commendable. However, beware of writing above your historical, grammar and punctuation level. Historical problem: The actual decision to drop the bomb was made because we thought that there would be fewer casualties on both sides than there would be by invading Japan not because of the attack on Pearl Harbor. Grammar: First sentence has an incorrect use of the word approve. There are also spelling errors which may be from typing too fast. Punctuation problems. In some cases, you have too many commas; a period in the wrong place or need semi colons.